1. Field of the Invention
The present invention relates to technology for manufacturing a semiconductor device, and, more particular, relates to an aligner evaluation system, an aligner evaluation method, an aligner evaluation program, and a method for manufacturing a semiconductor device used therein.
2. Description of the Related Art
A photolithography process is generally performed as a manufacturing process of semiconductor devices. Optical system errors attributable to aberration of a projection lens of an aligner used in the photolithography process and errors attributable to a difference in an illumination optical system represent unique values to each aligner. Accordingly, those errors vary delicately with aligners even of the same type. Therefore, if optimized exposure conditions for a new product in a particular aligner are applied to another aligner, it is possible that the latter aligner is not applicable to development of the new product (product development) because of inter-aligner variation in device pattern shapes formed on an exposure object, which is attributable to the optical system errors of each aligner. Accordingly, it is necessary to determine whether each aligner for performing the product development has an appropriate performance to facilitate the organization of a product development machine group.
Conventional device pattern simulation has been conducted without considering such optical system errors among the aligners. Accordingly, it has not been possible to determine from a group of aligners as to whether those aligners severally have appropriate performances for implementing an organization of a product development machine group for a new product. For this reason, conventionally, it has been necessary to carry out optimization of the exposure conditions for each of the aligners having delicately variable optical performances with respect to one another. Moreover, each of the aligners has been evaluated whether the aligner has the appropriate performances for implementing an organization of the product development machine group by a sequence of processes encompassing: exposure using a mask (reticle) for delineating device patterns of a product; development of the patterns; and measurement of shapes of the delineated patterns. As a consequence, product development has involved considerable time and effort.